Housing with internal locking arrangement

ABSTRACT

The present invention relates to a housing ( 10 ) with one first housing part ( 12 ) and one second housing part ( 14 ), which are reliably locked by an internal locking arrangement. The locking arrangement is suitable for various types and sizes of housings, particularly for the housings of electronic and display devices. The locking mechanism comprises a first locking element ( 30 ) being arranged moveably along an axis on the first housing part ( 12 ) and comprises a first engaging portion ( 32 ) that forms an engaged or disengaged state with a second engaging portion ( 42 ), which is arranged on the first housing part ( 12 ). A third engaging portion ( 52 ) arranged on the second housing part ( 14 ) is locked-in in the engaged state leading to a reliable locking of the first housing part ( 12 ) and second housing part ( 14 ), whereby the change between the engaged and disengaged state is realized by a movement of the first locking element ( 30 ).

This application is the U.S. National Phase application under 35 U.S.C.§ 371 of International Application No. PCT/EP2019/079319, filed on 28Oct. 2019, which claims the benefit of European Application Serial No.18204297.8, filed 5 Nov. 2018. These applications are herebyincorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates to a housing with an internal lockingarrangement. The internal locking arrangement finds application in avariety of housings of different size and type. Particularly of interestare housings for electronic and display devices, where the housing partsshould be tightly locked and the outer shell smooth without any holes orbulges.

BACKGROUND OF THE INVENTION

Housings exist in a variety of executions to protect the sensitive andfragile electric parts or just any kind of devices that are storedinside. These housings comprise at least two housing parts that areintended to be locked in the closed state of the housing. The lockingstructure should prevent the different housing parts from falling apartin the engaged state, where the housing is closed. Thus, a reliablelocking mechanism is needed. However, a simple opening of the housingshould also be possible to easily access the inner parts of the housing,i.e., for reparation or substitution of individual components of theenclosed device.

Many locking structures are using screws, which has the advantage thatthe device can be easily assembled or disassembled with a proper tool,i.e., a screwdriver. One disadvantage of using screws is that thelocking often results in an uneven fixation of the different housingparts. Hence, entry points for liquids and fluids can occur.Furthermore, the assembling and disassembling process is rathertime-consuming, because each locking element has to be loosened ortightened by its own. Another profound disadvantage of such a lockingstructure is that the locking element has to be accessible from theoutside of the housing. This can be solved by having locking elementsvisible on the outer shell of the housing, which is a satisfactorysolution for many housings. However, the housing of some particulardevices have to fulfil a diversity of requirements. Besides the simpleassembling process and the reliable locking mechanism, they shall bewatertight and the outer shell of the housing should be smooth. No holesor bulges on the outer shell of the housing are desirable. This isespecially of interest for housings that are in contact with fluids andliquids. The smooth shell enables a simple cleaning process, is veryhygienic and does not provide possible entry points for liquids.

A number of housings contain an internal locking arrangement based on asnap-fit mechanism with a male and female part, where these interlockingcomponents are pushed together. In comparison to other assemblytechniques they have particularly the advantage of speed. However,releasing the interlocking components with a tool from the outside isnot that straightforward and can easily lead to damages of the housing.

US 2015/0277487 A1 discloses a housing with an internal lockingmechanism where one actuation allows to engage or disengage the firstand second engaging portion. However, there remains a need to interlockhousing parts by a flexible, space-saving and mechanically simpleprocedure and in a reliable way.

U.S. Pat. No. 9,072,163 B2 discloses a housing assembly for a portableelectronic device, which includes a first body, a second body, a firstengaging member, a first resilient member and a first housing.

CN 104 184 849 A discloses a housing with one first housing part and onesecond housing part, which are reliably locked by an internal lockingarrangement. The locking arrangement is suitable for various types andsizes of housings, particularly for the housings of electronic anddisplay devices.

U.S. Pat. No. 9,063,696 B2 discloses a fixing mechanism, which includesa first engaging portion, a base, a first latch and a resilientcomponent.

US 2006/016675 A1 discloses a supporting device for the control buttonsof electronic instruments and electronic instruments adapting the same.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a housing comprisingat least two housing parts that can be simply assembled and disassembledand that provides a smooth shell of the housing without any holes orbulges. The internal locking mechanism of the housing should bespace-saving and concealed.

In a first aspect of the present invention a housing is presentedcomprising:

a first housing part;

a second housing part; and

an internal locking arrangement for engaging said first housing part andsecond housing part,

wherein said internal locking arrangement comprises:

a first locking element having a first engaging portion arrangedmoveably along an axis on an inner wall of the first housing part;

a second locking element having a second engaging portion arranged onthe inner wall of the first housing part; and

a third locking element having a third engaging portion arranged on aninner wall of the second housing part;

wherein said first engaging portion is configured to be moveable betweenan engaged state, in which the third engaging portion is locked-inbetween the first engaging portion and second engaging portion, and adisengaged state, in which the third engaging portion is not locked-in.

In a further aspect of the present invention a monitor device ispresented, particularly of interest for medical applications, comprisinga display for presenting information and a housing as disclosed herein.

Preferred embodiments of the invention are defined in the dependentclaims.

The present invention is based on the idea to have a housing, which maybe used in the medical field for display devices, with a reliable,space-saving internal locking arrangement for engaging a first and asecond housing part. The engaging portions can be brought into anengaged or disengaged state by just one simple actuation withoutaccessing the single engaging portions. In the engaged state bothhousing parts are interlocked with each other, while in the disengagedstate both housing parts are in a disjointed state. The interlocking ofthe housing parts is solved by a unidirectional movement, forward andbackward, of the first engaging portion and the further existence of athird engaging portion. The third engaging portion is locked-in by thefirst and a second engaging portion in the engaged state. Locked-inshall be understood such that the third engaging portion is located andpreferably clamped or trapped between the first and second engagingportion and in contact with the first and second engaging portion. Theopening force of the housing is perpendicular to the direction ofmovement of the first engaging portion, i.e. the mechanism is lockedreliably by itself.

The first, second and third engaging portions are arranged on a first,second and third locking element, respectively. The first and secondlocking element in turn are arranged on the inner wall of the firsthousing part and the third locking element is arranged on the inner wallof the second housing part. Thus, an opening of the housing foraccessing the engaging portions is not required and the outside of thehousing is smooth without any holes or bulges. It is noted that no partof the locking structure is visible from the outside. This is especiallybeneficial if the housing undergoes regular cleaning processes, which isthe case, e.g., in the medical field.

According to an embodiment, the housing comprises a plurality ofinternal locking arrangements. Only one internal locking arrangement maynot be sufficient to have a watertight housing in the gap between thefirst and second housing part. As the internal locking mechanism isvariable in the length of the first locking element as well as thenumber of engaging portions, the housing can be made suitable fordifferent types and sizes of housings. The locking arrangement isvariable and can be used all around in the housing. Furthermore, thespace-saving arrangement can be realized in a very compact way, whereinnot much space is needed for the engagement and disengagement.

According to another embodiment of the housing, only the first engagingportion is moveable along an axis. The other two engaging portions,namely the second engaging portion and the third engaging portion, arefixedly arranged on the inner wall of the corresponding housing parts.The second engaging portion is fixedly arranged on the inner wall of thefirst housing part and the third engaging portion is fixedly arranged onthe second housing part. Thus, only the first engaging portion needs tobe moved along an axis for switching between the engaged and disengagedstate, which is a mechanically simple procedure.

According to another embodiment of the housing, the second engagingportion is configured as a female receiving portion. Thus, the secondengaging portion has any kind of opening with a certain shape thatcorresponds to the shape of the first engaging portion, which isconfigured as a male penetrating portion. The first engaging portionpenetrates into the second engaging portion in the engaged state by aunidirectional movement.

Preferably, the shape of the first engaging portion corresponds with theshape of the second engaging portion and is further concretized byhaving the shape of a bar, tip, cylinder, spike or pin. The secondengaging portion in turn is configured as the corresponding femalereceiving portion with a preferable shape of a lug, recess, groove orbore.

According to another embodiment of the housing, the movement of thefirst engaging portion along one axis can be parallel to thelongitudinal axis of the first locking element or inclined with respectto the longitudinal axis of the first locking element. An angle up to45° may be practicable, wherein the second engaging portion is stillforming the female receiving portion. Hence, the second engaging portionis equally inclined with respect to the longitudinal axis of the firstlocking element.

According to another embodiment of the housing, the first lockingelement has a first mounting element, the second locking element has asecond mounting element and the third engaging portion is arranged at aposition on the inner wall of the second housing part that allows tolock in the third engaging portion by covering an upper surface of saidthird engaging portion with the first engaging portion.

According to this embodiment of the housing, the first engaging portionis not configured to be directly moveable since it is fixedly arrangedon the first mounting element or formed integrally with the firstmounting element. The mounting element in turn is fixedly arranged onthe first locking element or formed integrally with the first lockingelement. Thus, a movement of the first locking element is configured toswitch between the engaged and disengaged state.

The first engaging portion is preferably arranged substantiallyperpendicular to the front surface of the first mounting element.Hereby, the front surface of the first mounting element, an undersurfaceof the first engaging portion and the front surface of the secondmounting element are configured to enclose a three-dimensional enclosedspace, in which the third engaging portion is locked-in in the engagedstate. Locked-in shall be understood such that the surface of the thirdengaging portion is in contact with the front surface of the firstmounting element, an undersurface of the first engaging portion and thefront surface of the second mounting element. Thus, the enclosed spaceis completely filled by the third engaging portion.

Preferably, the third engaging portion filling this enclosed space hasthe shape of a hook, bar, tip, pin or spike.

Further, an inner surface of the second engaging portion as well as anupper surface of the third engaging portion limit the movement of thefirst engaging portion in the engaged state perpendicular to themovement direction of the first engaging portion. Said inner surface ofthe second engaging portion as well as the upper surface of thirdengaging portion are in contact with the first engaging portion in theengaged state. Thus, the locking arrangement is reliably locked byitself.

According to another embodiment, the housing further comprises aninternal opening tool being configured to move the first engagingportion manually into the engaged or disengaged state. The internalopening tool may be concealed in the housing, but may also be arrangedsuch that it is accessible from a particular (already existing orseparately provided) opening of the housing, such as a cooling slit.

Preferably, this internal opening tool comprises a first attachingelement and a second attaching element, wherein the space between thefirst attaching element and second attaching element is configured totrap the first mounting element in order to switch between the engagedand disengaged state by a manual movement of the internal opening tool.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will be apparent from andelucidated with reference to the embodiment(s) described hereinafter. Inthe following drawings

FIG. 1 shows a perspective view of a preferred embodiment of a housingaccording of the present invention in a closed state;

FIG. 2 shows a cross sectional view of the housing shown in FIG. 1 ;

FIG. 3 shows a perspective view of the housing shown in FIG. 1 in anopen state;

FIG. 4 shows an enlarged view of an embodiment of an internal lockingarrangement in an engaged state;

FIG. 5 shows an enlarged view of the internal locking arrangement shownFIG. 4 in a disengaged state;

FIG. 6 shows a perspective view of the internal locking arrangementshown in FIG. 4 and an internal opening tool;

FIG. 7 shows another perspective view of the internal lockingarrangement shown in FIG. 4 in an engaged state; and

FIG. 8 shows a cross-sectional view of the internal locking arrangementshown in FIG. 4 in an engaged state.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1 shows a perspective view of an embodiment of a housing 10according to the present invention in a closed state. FIG. 2 shows acorresponding cross-sectional view of said embodiment of the housing 10.The housing 10 comprises a first housing part 12 and a second housingpart 14 and is shown in a closed state, in which the housing parts 12,14 are joined together. The housing 10 may be made of plastic and/ormetal and configured for housing a display or monitor, but the housingmay be use for housing other components as well. In this embodiment thehousing 10 comprises an opening 80, e.g., to accommodate a display of apatient monitor to display patient-relevant data.

The housing parts 12, 14 are joined together by one or more internallocking arrangements 20. Generally, one single internal lockingarrangement may be sufficient, but multiple internal locking arepreferably provided around the circumference of the housing to improvethe stability and security of the closing of the housing. The preferredposition of the locking arrangement 20 is close to the boundary of thefirst housing part 12 and the second housing part 14 and close to theinner wall 16 of the first housing part 12 and the inner wall 18 of thesecond housing part 14 in order to provide an optimized distribution offorce. Other arrangement and positions are, however, possible as well.

The internal locking arrangement 20 is partly arranged on the inner wall16 of the first housing part 12 and partly on the inner wall 18 of thesecond housing part 14. In FIGS. 1 and 2 the internal lockingarrangement 20 is in an engaged state providing a jointed state of thefirst housing part 12 and the second housing part 14. In this state anaccidental opening of housing 10 is impossible or at least unlikely.Only switching the internal locking arrangement 20 into a disengagedstate enables to disjoint the first housing part 12 and the secondhousing part 14 by subsequently moving the second housing part 14 awayfrom the first housing part 12. Preferably, only one actuation is neededto switch between the engaged and disengaged state because all lockingarrangements are interlocked.

The first housing part 12 and the second housing part 14 are shown in adisjointed state in FIG. 3 , in which the housing 10 is in an openstate. As shown there, the internal locking arrangement 20 comprises afirst locking element 30 and a second locking element 40, which are botharranged on the first housing part 12 (preferably on an inner wall 16),and a third locking element 50, which is arranged on the second housingpart 14 (preferably on an inner wall 18). An internal opening tool 100is provided to enable opening of the housing. Details of theconstructing and function of the locking elements 30, 40, 50 and of theinternal opening tool 100 will be explained below with reference toFIGS. 4-8 .

FIG. 4 shows an enlarged view of an embodiment of an internal lockingarrangement 20 in an engaged state, in which the first housing part 12and the second housing part 14 are in a jointed state. FIG. 5 shows anenlarged view of said internal locking arrangement 20 in a disengagedstate, in which the first housing part 12 and the second housing part 14are in a disjointed state. FIG. 6 shows a perspective view of saidinternal locking arrangement 20 and an internal opening tool 100.Another perspective view of said internal locking arrangement 20 withoutthe internal opening tool 100 and with both housing parts is shown inFIG. 7 . FIG. 8 shows a cross-sectional view of the internal lockingarrangement 20 in the engaged state.

The first locking element 30 is arranged on the first housing part 12.In this embodiment the first locking element 30 comprises a firstengaging portion 32, which is fixedly arranged on a first mountingelement 34. In this embodiment, the first engaging portion 32 is formedintegrally with the first mounting element 34. The first mountingelement 34 is, in this embodiment, formed integrally on a slidingelement 35, preferably as erected portion. The sliding element 35 may beconfigured such that it connects multiple first locking elements 30,i.e. the sliding element 35 is common to multiple first locking elements30 arranged along the same edge portion of the first housing part 12.

The first locking element 30 arranged moveably along an axis 70 on theinner wall 16 of the first housing part 12 and configured to be moveableforward and backward along this axis 70. Preferably, the sliding element35 is configured like slide or carriage that is configured to slidealong a track or guide rail 75 that is fixed to the inner wall 16 of thefirst housing part 12 or to slide directly along the inner wall 16 ofthe first housing part 12. The axis 70 is preferably arranged parallelto the longitudinal axis of the first locking element 30.

The second locking element 40 is fixedly arranged on the inner wall 16of the first housing part 12 and works as an attachment for the firstlocking element 30 and as the corresponding counterpart for the firstlocking element 30 in the locking process. The second locking element 40comprises a second mounting element 44, which in turn comprises a secondengaging portion 42, which is formed integrally with the second mountingelement 44 in the specific embodiment. The second mounting element 44 isoriented perpendicular to the longitudinal axis of the second lockingelement 40 and contains an opening, which represents the second engagingportion 42.

The third locking element 50 is arranged fixedly on the inner wall 18 ofthe second housing part 14. It comprises a third engaging portion 52that is preferably oriented perpendicular to the longitudinal axis(which is preferably parallel to the movement axis 70) of the firstengaging portion 32 in the jointed state of housing 10. The inner wall18 of the second housing part 14 is preferably oriented perpendicular tothe inner wall 16 of the first housing part 12.

As particularly shown in FIG. 7 , the sliding element 35 basically workslike a sliding gate and has a longitudinal, e.g. U-shaped, cavity 37, inwhich the second locking element 40 is placed. The second lockingelement 40 is fixedly attached to the inner wall 16 of the first housingpart by a screw 49. Thus, the second locking element 40 holds thesliding element 35 and hence the complete first locking element 30towards the inner wall 16 of the first housing part 12, without limitingthe movement of the first locking element 30 along said axis 70. Inother words, the first locking element 30 is indirectly clamped towardsthe inner wall 16 of the first housing part 12 by the second lockingelement 40.

The movement of the first locking element 30 allows to switch betweenthe engaged and disengaged state of the locking arrangement 20. Hence, amechanically simple procedure enables to reliably joint the firsthousing part 12 and second housing part 14 together. Hereby, an internalopening tool 100, which may be accessible from the outside of thehousing, i.e., by any kind of slit or opening in the first housing part12 or second housing part 14, is configured to move the first lockingelement 30.

Said internal opening tool 100 is particularly shown in FIG. 6 . In thisembodiment it may be concealed in the housing enabling a smooth outershell of housing 10. This is of particular interest for housings used inthe field of medical applications, where regular cleaning processes areimportant. The internal opening tool 100 may be a gearing mechanism or alever. A fixed gearing results from the fixed arrangement of theinternal opening tool 100 by, e.g., a screw through opening 101 in theinternal opening tool 100 on one of the housing parts, whereas afloating bearing results from the first attaching element 102 and secondattaching element 104, which are configured to move the first lockingelement 30 by locking in the first mounting element 34. By varying theposition of the fixed bearing, the length of the lever or the positionof the floating bearing on the first locking element 30, free relocationof handling position is possible and the force can be adjusted.Likewise, by varying the length of the lever, the position of thefloating bearing between the first locking element 30 and the internalopening tool 100, the position of the fixed bearing and the geometry ofthe internal opening tool 100, enables to select the position of thehandling and thus adapt it to the present internal design of thehousing.

In this particular embodiment, the internal opening tool 100 comprises afirst attaching element 102 and a second attaching element 104, whichare configured like fingers. The space 106 between the first attachingelement 102 and the second attaching element 104 is configured to lockin the first mounting element 34. Thus, the first locking element 30 canbe moved between the engaged state (shown in FIG. 4 ) and disengagedstate (shown in FIG. 5 ).

As shown in FIGS. 4 to 8 , the first engaging portion 32 has the shapeof bar, tip, cylinder, spike or pin and is configured as a malepenetrating portion for the second engaging portion 42, which is formingthe corresponding female receiving portion. Thus, the second engagingportion 42 has the shape of a lug, recess, groove or bore and enclosesthe first engaging portion 32 in the engaged state (see FIGS. 4 and 8 ).The tip of the first engaging portion 32 crosses the second engagingportion 42 completely in the engaging process and becomes apparent atthe backside 47 of the second mounting element 44. From the engaged tothe disengaged state, the first locking element 30 must be moved a fewmillimeters, but the mechanism as a whole realizes a locked housing 10across a distance of several centimeters, from where a next combinationof first engaging portions 32, second engaging portions 42 and thirdengaging portions 52 may be applied. By having a plurality of internalopening tools 100, which might be coupled to each other or might beseparate components, the slight movement of the first locking element 30can lead to a closing mechanism of various sides of the housing 10.Thus, the first housing part 12 and second housing part 14 can beassembled simply and fast by one actuation along the single axis 70.

It should be noted that the first engaging portion 32 and the secondengaging portion 42 are configured as a male penetrating portion and afemale receiving portion, respectively, according to the embodimentsshown in FIGS. 4 to 8 . The present invention is, however, notrestricted to such exemplary embodiments. In general, the shape of thefirst engaging portion 32 and the shape of the second engaging portion42 may also be configured differently, in particular such that theseportions do not form male penetrating and female receiving portions. Thefirst engaging portion 32 may, e.g., be a pin, while the second engagingportion 42 may, e.g., be another pin formed integrally with the secondmounting element 44, instead of being a lug or a bore as shown in FIGS.4 to 8 . According to said embodiment, the first engaging portion 32 maycontact the second engaging portion 42 (not shown in FIGS. 4 to 8 )instead of penetrating a lug or a bore in the engaged state. Thisembodiment is also configured to lock-in the third engaging portion 52between the first engaging portion 32 and the second engaging portion 42and thus also provides a concealed and space-saving locking mechanism.

FIG. 4 shows that the third engaging portion 52 is locked-in by coveringan upper surface 58 of said third engaging portion 52 with the firstengaging portion 32. In the specific embodiment, the third engagingportion 52 is arranged between a front surface 36 of the first mountingelement 34 facing towards the second mounting element 44 and the frontsurface 46 of the second mounting element 44 facing towards the frontsurface 36 of the first mounting element 34. Thus, the position of thethird engaging portion 52 on the inner wall 18 of the second housingpart 14 is predetermined so that the third engaging portion 52 becomeslocked-in in the engaged state.

Furthermore, in this embodiment the first engaging portion 32 isarranged substantially perpendicular to the front surface 36 of thefirst mounting element. Hence, the third engaging portion 52 is not onlylocked-in between a front surface 36 of the first mounting element 34and the front surface 46 of the second mounting element 44, but alsobelow the undersurface 38 of the first engaging portion 32. In thatcase, the movement of the first engaging portion 32 is reliably lockedin the direction perpendicular to the movement direction of the firstlocking element 30 and thus the internal locking arrangement 20 exhibitsa certain self-locking mechanism. Specifically, an inner surface 48 ofthe second engaging portion 42 and an upper surface 58 of the thirdengaging portion 52 limit the movement of the first engaging portion 32in the engaged state as shown in FIG. 8 . FIG. 8 further reveals thatscrew 49 attaches the second mounting element 40 to a connecting element90, which is arranged on the first housing part 12. Thus, the positionof the second locking element 40 is predetermined and a movement of thesecond locking element 40 is impossible under the condition that screw49 is firmly tightened.

The locked state is released by moving the first locking element 30backward along the movement axis 70. FIG. 5 shows that the thirdengaging portion 52 is placed in an enclosed space 60, which is enclosedby the first mounting element 34, second mounting element 44 and thethird engaging portion 52 in the engaged state. The first housing part12 and the second housing part 14 can be easily disjointed in thedisengaged state of the locking arrangement 20.

It is to be noted that the first engaging portion 32 and the secondengaging portion 42 may take other forms different to the embodimentdescribed here. Preferably, the form of the second engaging portion 42enables the second engaging portion 42 to form a female receivingportion for the first engaging portion 32, which is forming the malepenetrating portion. Moreover, the third engaging portion 52 may beformed in a different way. Preferably, this third engaging portion 52 isformed to fit in the enclosed space 60.

With the present invention, a mechanism for opening and closing ahousing can be realized inside of the housing, concealed from theoutside, in minimal installation space, and independently from thehandling position for operating. In principle the locking mechanism canbe applied with all types of housings. Examples of this include housingsfor electronic devices with a metal or plastic housing. As thismechanism is variable in dimension, e.g. in length of the slidingelement and the amount of engaging portions, it can be made suitable fordifferent types and sizes of housings.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, such illustration and descriptionare to be considered illustrative or exemplary and not restrictive; theinvention is not limited to the disclosed embodiments. Other variationsto the disclosed embodiments can be understood and effected by thoseskilled in the art in practicing the claimed invention, from a study ofthe drawings, the disclosure, and the appended claims.

In the claims, the word “comprising” does not exclude other elements orsteps, and the indefinite article “a” or “an” does not exclude aplurality. A single element or other unit may fulfill the functions ofseveral items recited in the claims. The mere fact that certain measuresare recited in mutually different dependent claims does not indicatethat a combination of these measures cannot be used to advantage.

Any reference signs in the claims should not be construed as limitingthe scope.

The invention claimed is:
 1. A housing comprising: a first housing part;a second housing part; and an internal locking arrangement for engagingsaid first housing part and second housing part, wherein said internallocking arrangement comprises: a first locking element comprising afirst engaging portion arranged moveably along an axis on an inner wallof the first housing part, and a first mounting element; a secondlocking element comprising a second engaging portion arranged on theinner wall of the first housing part, and a second mounting element; anda third locking element having a third engaging portion arranged on aninner wall of the second housing part, the third engaging portion beingarranged at a position on the inner wall of the second housing part thatallows locking in the third engaging portion by covering an uppersurface of said third engaging portion with the first engaging portion,wherein said first engaging portion is configured to be moveable betweenan engaged state, in which the third engaging portion is locked-inbetween the first engaging portion and second engaging portion in anenclosed space, which is formed by the first engaging portion and thesecond engaging portion, and a disengaged state, in which the thirdengaging portion is not locked-in.
 2. The housing according to claim 1,wherein the housing comprises a plurality of internal lockingarrangements.
 3. The housing according to claim 1, wherein the secondengaging portion is fixedly arranged on the inner wall of the firsthousing part and the third engaging portion is fixedly arranged on theinner wall of the second housing part.
 4. The housing according to claim1, wherein the second engaging portion is configured as a femalereceiving portion for receiving the first engaging portion, which isconfigured as a corresponding male penetrating portion.
 5. The housingaccording to claim 1, wherein the first engaging portion has the shapeof a bar, tip, cylinder, spike or pin and the second engaging portionthe shape of a lug, recess, groove or bore.
 6. The housing according toclaim 1, wherein the axis along which the first engaging portion ismoveable is parallel to the longitudinal axis of the first lockingelement or inclined with respect to the longitudinal axis of the firstlocking element at an angle equal to or less than 45°.
 7. The housingaccording to claim 1, wherein the first engaging portion is fixedlyarranged on the first mounting element or formed integrally with thefirst mounting element.
 8. The housing according to claim 7, wherein thefirst engaging portion is arranged substantially perpendicular to thefront surface of the first mounting element.
 9. The housing according toclaim 7, wherein the front surface of the first mounting element, anundersurface of the first engaging portion and the front surface of thesecond mounting element are configured to enclose an enclosed space, inwhich the third engaging portion is locked-in in the engaged state. 10.The housing according to claim 9, wherein the third engaging portion hasthe shape of a hook, bar, tip, pin or spike, and fits into the enclosedspace.
 11. The housing according to claim 10, wherein an inner surfaceof the second engaging portion as well as the upper surface of the thirdengaging portion limit the movement of the first engaging portion in theengaged state.
 12. A patient monitor device, comprising a display, andthe housing of claim 1 for housing the display.
 13. A housingcomprising: a first housing part; a second housing part; an internallocking arrangement for engaging the first housing part and secondhousing part, the internal locking arrangement comprising: a firstlocking element comprising a first engaging portion arranged moveablyalong an axis on an inner wall of the first housing part; a secondlocking element comprising a second engaging portion arranged on theinner wall of the first housing part; and a third locking elementcomprising a third engaging portion arranged on an inner wall of thesecond housing part; and an internal moveable opening tool beingaccessible from an opening, in particular a cooling slit, of the firsthousing part and/or of the second housing part, wherein: the internaltool comprises a first attaching element and a second attaching elementto lock in a first mounting element of the first locking element to movethe first engaging portion into the engaged state and the disengagedstate by a movement of the moveable opening tool; the first engagingportion is configured to be moveable between an engaged state, in whichthe third engaging portion is locked-in between the first engagingportion and second engaging portion in an enclosed space, which isformed by the first engaging portion and the second engaging portion,and a disengaged state, in which the third engaging portion is notlocked-in.
 14. The housing according to claim 13, wherein the internalopening tool comprises a first attaching element and a second attachingelement, wherein the space between the first attaching element and thesecond attaching element is configured to lock in the first mountingelement allowing to switch the first engaging portion between theengaged state and the disengaged state by movement of the internalopening tool.
 15. The housing according to claim 13, wherein the housingcomprises a plurality of internal locking arrangements.
 16. The housingaccording to claim 13, wherein the second engaging portion is fixedlyarranged on the inner wall of the first housing part and the thirdengaging portion is fixedly arranged on the inner wall of the secondhousing part.
 17. The housing according to claim 13, wherein the secondengaging portion is configured as a female receiving portion forreceiving the first engaging portion, which is configured as acorresponding male penetrating portion.
 18. The housing according toclaim 13, wherein the first engaging portion has the shape of a bar,tip, cylinder, spike or pin and the second engaging portion the shape ofa lug, recess, groove or bore.
 19. The housing according to claim 13,wherein the axis along which the first engaging portion is moveable isparallel to the longitudinal axis of the first locking element orinclined with respect to the longitudinal axis of the first lockingelement at an angle equal to or less than 45°.
 20. A patient monitordevice, comprising: a display; and the housing of claim 13 for housingthe display.